(Pocket-lint) - Amazon announced its own 4K streaming box at an event last week in the form of an upgraded version of Fire TV and Nvidia is expected to bring its Shield Android TV set-top-box to the UK a some point, which also has 4K Ultra HD streaming abilities, so it comes as no surprise to learn that Roku is rumoured to do the same before the year is out.

Rumours have it that the streaming box specialist is soon to unveil an ultra high definition-capable Roku 4 (or Roku 4K, so to speak) in order to compete directly with Amazon, Nvidia and several other media player manufacturers that have also added UHD support in recent months.

A couple of clues have been spotted online and in Roku's own channel line-up to suggest a new device is on the way and that it could offer UHD ouput.

CinemaNow posted details of how to claim four free HD rentals for Roku 4 purchasers - which confirms the name - before pulling that page. Then Roku's own official UK Channel Store listed a channel called "4K Showcase", suggesting that 4K content will soon be available to stream.

It'll be a real coup for Roku to play its 4K hand soon, with the new Apple TV still yet to be made available to buy. The new Apple TV, of course, does not support 4K - at least, not according to Apple's website or the information released during its unveiling.

Writing by Rik Henderson.